• ISSN 1008-505X
  • CN 11-3996/S
叶协锋, 周涵君, 于晓娜, 张晓帆, 李志鹏, 付仲毅, 孟琦. 热解温度对玉米秸秆炭产率及理化特性的影响[J]. 植物营养与肥料学报, 2017, 23(5): 1268-1275. DOI: 10.11674/zwyf.16467
引用本文: 叶协锋, 周涵君, 于晓娜, 张晓帆, 李志鹏, 付仲毅, 孟琦. 热解温度对玉米秸秆炭产率及理化特性的影响[J]. 植物营养与肥料学报, 2017, 23(5): 1268-1275. DOI: 10.11674/zwyf.16467
YE Xie-feng, ZHOU Han-jun, YU Xiao-na, ZHANG Xiao-fan, LI Zhi-peng, FU Zhong-yi, MENG Qi. Physiochemical properties and yields of corn-stalk-biocharunder different pyrolyzed temperatures[J]. Journal of Plant Nutrition and Fertilizers, 2017, 23(5): 1268-1275. DOI: 10.11674/zwyf.16467
Citation: YE Xie-feng, ZHOU Han-jun, YU Xiao-na, ZHANG Xiao-fan, LI Zhi-peng, FU Zhong-yi, MENG Qi. Physiochemical properties and yields of corn-stalk-biocharunder different pyrolyzed temperatures[J]. Journal of Plant Nutrition and Fertilizers, 2017, 23(5): 1268-1275. DOI: 10.11674/zwyf.16467

热解温度对玉米秸秆炭产率及理化特性的影响

Physiochemical properties and yields of corn-stalk-biocharunder different pyrolyzed temperatures

  • 摘要:
    目的通过对不同热解温度条件下玉米秸秆炭理化特性的分析,探索玉米秸秆炭具有较高利用价值的炭化温度。
    方法以玉米秸秆为原料,采用低氧升温炭化法,在不同热解温度下 (100℃、200℃、300℃、400℃、500℃、600℃、700℃、800℃) 分别炭化2 h,制备生物炭,收集并测定了固体产物生物炭产率及特性。
    结果生物炭的产率随热解温度的升高逐渐降低。生物炭全碳含量和碳氮比随热解温度升高而升高,全氮含量在400℃以后随热解温度升高而降低。阳离子交换量 (CEC) 在400℃~600℃达到较高水平,为70.87~83.48 cmol/kg。随热解温度升高,玉米秸秆炭表面碱性含氧官能团增加、酸性含氧官能团减少,pH随着热解温度的升高逐渐增加,当温度达到400℃及400℃以上时呈碱性甚至强碱性。红外光谱分析表明,热解温度达到500℃时,纤维素和半纤维素已经完全分解;高温热解使玉米秸秆中–CH3、–CH2、–OH、–C=O间发生缔合或消除,促进芳香基团的形成。随着热解温度的升高,玉米秸秆炭的比表面积和比孔容均是先变大后变小,孔径先变小后变大,在400℃~600℃条件下,玉米秸秆炭的孔隙相对较为丰富,不同热解温度下玉米秸秆炭的比表面积和比孔容呈极显著正相关关系(P < 0.01)。
    结论综合各项指标,玉米秸秆的最佳热解温度为400℃~500℃,此温度下制备的生物炭产出率相对较高,氮、碳养分损失少,生物炭的理化性能和养分利用均达到最优。

     

    Abstract:
    Objectives The physiochemical properties of corn-stalk-biochar were largely determined by the carbonization temperature. The aim of the experiment was to investigate the yields and physiochemical properties of corn-stalk-biochar at different pyrolyzed temperatures (100℃–800℃), looking for the suitable temperature in which biochar has a high use value.
    MethodsCorn-stalk-biochar was prepared through the hypoxia carbonization method. The furnace temperatures were set at 100℃, 200℃, 300℃, 400℃, 500℃, 600℃, 700℃ and 800℃, respectively, and the rate of heating up was 20℃/min and finally held at that temperature for 2 hours. We studied the properties, including pH, total N and total C content, and CEC of biochar.
    ResultsThe yields of corn-stalk-biochar were decreased with the rising of pyrolysis temperature. The total C contents were increased with the increase of pyrolysis temperature, the total N contents started to decrease when the temperature was higher than 400℃. The CEC of corn-stalk-biochar reached peak values between 400℃–600℃, which were 70.87–83.48 cmol/kg. With the increase of carbonization temperature, the alkaline functional groups contents on the corn-stalk-biochar surface were increased significantly, while the acidic functional groups contents were reduced significantly. The pH values of corn-stalk-biochar became alkaline after 400℃ and would continue to increase to strong alkaline with the further increase of temperature. When the pyrolysis temperature reached 500℃, the cellulose and hemicellulose were completely decomposed, and the groups of –OH, –CH3, –CH2, –C=O would be associated or eliminated to form new aromatic groups. With the carbonization temperature increasing, the specific surface area and pore volumes of corn-stalk-biochar were both increased firstly and then declined. However, the pore sizes showed an opposite trend. The porosity of corn-stalk-biochar was relatively more abundant at 400℃–600℃. The specific surface area showed a significant highly positive correlation with the pore volume.
    Conclusions Comprehensively considering the effects of yields and physiochemical properties, the optimum carbonization temperature of corn-stalk-biochar should be remained at 400℃–500℃.

     

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